MOLLUSCS

Slugs, snails, oysters, clams, squid, octopuses, and
cuttlefish are very different to look at, but they are all molluscs. They have
a ribbon-like tongue, called the radula, covered in thousands of denticles
(tiny teeth). Many have a calcium-carbonate shell. Most molluscs live in water,
but slugs and snails live on land.

The African land snail can be 30 cm (12 in) long. Like all snails,
it carries a coiled shell on its back and withdraws into the shell when
threatened. It moves slowly on a large, muscular foot, using slime to ease the
way. Its mouth, underneath its head, contains the denticle-covered radula.

The blue-ringed octopus is a mollusc that does not have a shell. It
has a large brain and big eyes. It uses its eight arms to crawl, but also
squirts water from inside its body to move more quickly.

PHYLUM: MOLLUSCA

Molluscs have unsegmented bodies generally protected by a shell.
There are more than 50,000 species in seven classes, including the following
five common ones.